The temperatures fluctuate dramatically on the NFL head coach hot seat.

Tampa Bay’s Greg Schiano appeared to be a lock to be the first to be fired, even before the end of the season. But after further review, he has been removed for now from the hot seat.

In rookie Mike Glennon, Schiano has found his franchise quarterback, and his team is playing hard for him, and turning around a wretched season.

Marquee franchises such as the Cowboys and Redskins could be in play for upheaval in this year’s high-stakes game of musical coaches.

Is it any wonder the unrelenting stress of the job took its toll this season on John Fox (heart) and Gary Kubiak (mini-stroke)? This is an immediate gratification league, filled with impatient owners who have adopted the Lombardian creed of: “Winning isn’t everything, it’s the only thing” (for our fan base paying these obscene prices, yuk yuk yuk).

Consider that since Woody Johnson hired Rex Ryan in 2009, 20 of the NFL’s 31 other franchises have hired new head coaches (the Lions hired Jim Schwartz in ‘09 as well). The NFL stands for Not For Long for players and coaches both.

THE HOT SEAT

MIKE SHANAHAN (Redskins): The 2012 division title seems an eternity ago, and his relationship with Robert Griffin III reminds no one of Bill Belichick and Tom Brady. And did we mention owner Daniel Snyder never has had a head coach last more than four seasons since taking ownership of the club in 1999? That next season is the fifth and final season of Shanahan’s five-year, $35 million contract? That he will finish 2013 with three losing seasons in four? That his defense and special teams are a mess?

JASON GARRETT (Cowboys): Owner Jerry Jones vowing in late November that Garrett will return as coach does not mean Jones won’t reserve the right to change his mind in January (ask Wade Phillips). By all accounts, Jones is fond of Garrett, but the shelf life for head coaches in Dallas is around four years, and Garrett just completed three years on the job after taking over for Phillips in November 2010. Ultimately, this will be QB Tony Romo’s call. If Jones gets his four-year itch, and Romo launches into a passionate defense of his former play-caller, Jones will relent. Even if Bill Parcells decides he wants to come back one more time.

His record: 28-24.

Odds of being fired: 25-1

JIM SCHWARTZ (Lions): Avoided disaster by beating the Matt Flynn Packers on Thanksgiving. Matthew Stafford and Ndamukong Suh were first overall picks in the draft, and Calvin Johnson was the second player picked in 2007, behind JaMarcus Russell (Raiders). Yet the Lions still are perceived as an undisciplined, dirty outfit that underachieves and lacks maturity, poise and mental toughness. This is Year 5 of the program, and Motown still is waiting for its first playoff win in 20 years. Aaron Rodgers’ broken collarbone opened the door for a Detroit takeover, but there only will be remorse if opportunity is lost.

His record: 29-47.

Odds of being fired: 10-1

JOE PHILBIN (Dolphins): The 3-0 start raised expectations, but then the Richie Incognito-Jonathan Martin scandal took center stage and shined an unflattering light on the franchise. Owner Stephen Ross’ public remarks would seem to imperil GM Jeff Ireland, but he’ll wait to act until after the NFL’s Ted Wells finishes his investigation. The play calling hasn’t pleased deep threat Mike Wallace, but if the arrow on QB Ryan Tannehill is pointing up, Philbin should survive, as long as he isn’t implicated in the bullying fiasco.

His record: 12-15.

Odds of being fired: 6:1

DENNIS ALLEN (Raiders): If Son of Al Davis can fire talented PR director Zak Gilbert, he can fire Allen with two more years left on his contract. The quarterback position — from Matt Flynn to Terrelle Pryor to Matt McGloin — still is an eyesore. The franchise’s first head coach with a defensive background since John Madden, don’t expect him to get the chance to be John Madden — when Allen was hired as the youngest head coach in the league, he became the ninth Raiders head coach since the team returned from Oakland in 1995.

His record: 8-20.

Odds of being fired: 4:1

MIKE MUNCHAK (Titans): He won’t have to worry if backup QB Ryan Fitzpatrick leads the Titans to the sixth seed, but the inability of starter Jake Locker to stay on the field has led to another season of mediocrity. Remember, Munchak, who has one year remaining on his contract, barely survived the late Bud Adams’ guillotine when he ended the 2012 season with a 15-17 record. Adams’ son-in-law, new boss Tommy Smith, likely is to remember the playoffs-or-bust mandate.

Munchak’s record: 20-23.

Odds of being fired: 1:2

GARY KUBIAK (Texans): The question when the season began was “Can Matt Schaub take the Texans to a Super Bowl?” The answer was a resounding “No,” and apoplectic fans wound up burning Matty Vice’s jersey. The loss last Sunday to the Jaguars may have been the final nail in the coffin. There was a recent report that the front office was frustrated with Kubiak, and as much as owner Bob McNair likes him, you wonder whether he will want someone who suffered a mini-stroke to nurture the rookie quarterback the club will be looking to draft high.

His record: 61-62.

Odds of being fired: 1:1

LESLIE FRAZIER (Vikings): Nice guys finish last in the NFC Central twice in the last three years. The 2012 playoff berth helps, but the failure to develop QB Christian Ponder has led to chaos at the most important position. Will GM Rick Spielman trust a defensive-minded head coach to groom the next franchise quarterback? Adrian Peterson is running out of time.

His record: 18-31.

Odds of being fired: 1:3

REX RYAN (Jets): The one scenario that could doom him is losing the last five games and Geno Smith continuing to flounder. Johnson and GM John Idzik would have a rough time bringing back a coach without a playoff appearance three straight years. A 7-9 finish with a rookie quarterback showing signs of improvement and a young, ascending defense could be enough to save him given that he seems to have a good working relationship with the rookie GM. Ryan is 19-24 in his past 43 games.